【作者】 张振；

【导师】 李维诗；

【作者基本信息】 合肥工业大学 ， 仪器仪表工程（专业学位）， 2016， 硕士

【摘要】 采用金属粉末材料直接打印功能零件是3D打印/增材制造技术的一个主要发展方向。为了改善制件性能,本文突破现有的填充式扫描路径,研究了一种非填充式路径规划方法。采用传统填充式扫描路径对金属粉末材料进行3D打印时,已成型层容易出现翘曲变形甚至开裂现象。本文研究的一个目的在于通过采用新型扫描路径,抑制这种变形开裂现象。同时,在打印过程中,阶梯效应是所有3D打印技术无法克服的一个原理性缺点,3D打印后零件需要进行后处理,因此必须保证留有一定的加工余量,这样才能确保零件的最终精度。本文还研究了一种保证3D打印后零件加工余量非负的切片处理方法。全文共分五章：第一章介绍了该领域国内外的研究现状,分析了本文的研究意义,最后介绍了本文的主要研究内容；第二章介绍了STL格式文件读取与显示方法,其中包括STL文件的结构分析,文件的读取流程,以及模型显示方法。本文在读取该文件过程中建立三角网格拓扑结构,构建了三角面片毗邻信息；第三章实现了对三角网格模型的切片处理。根据设置的间距,采用一系列与x-y坐标平面平行的平面与模型相交,获得模型的一系列截面轮廓线,进一步建立单层截面内轮廓的拓扑关系,得到正确的填充区域；第四章根据第三章中获得的填充区域数据,利用单层截面轮廓线裁剪正三角形网格模板,得到三组平行的扫描线,构成三角网格形整体路径,最终转换成在3D打印机可执行的CLI格式文件；第五章对本文进行了总结和展望。总结了本文所讲述的主要内容,并对进一步的研究进行了分析和展望。更多还原

【Abstract】 One of the main directions of additive manufacturing is to print functional components directly using metal powder materials. In order to improve the functionality of the component, this thesis focuses on a kind of non-fill path planning instead of the traditional fill scanning. When the metal powder is melted with the traditional scanning path and solidified, warping and even cracking may appear in the formed layers. One target of this research is to suppress the warping and cracking.Meanwhile, the staircase effect is a fundamental disadvantage and could not be avoided for all 3D printing techniques. Additional sandblasting, grinding, etc. are generally needed for 3D printed components. It is therefore necessary to leave enough allowance to guarantee the accuracy of the final components. In this thesis, a method guaranteeing the allowance of obtained components to be non-negative has been proposed. This thesis is divided into five chapters:In the first chapter, related works with an emphasis on slice processing and scanning path planning are reviewed. The significance of this research is also analyzed. Finally, the main contents of this thesis are introduced.In the second chapter, the methods to analyze the STL file structure, read the file as well as display the model are introduced. The topology of the mesh is constructed to get the adjacency of triangular facets.In the third chapter, the slicing of mesh models is realized. The intersections between the model and a series of evenly spaced planes parallel to the X-Y plane are computed to get a series of cross-sectional contours of the model. The topological relationship of the contours in each slice is constructed to determine the correct filling area;In the fourth chapter, a regular triangle template is trimmed by the contours in each slice with respect to the filling area to get three groups of parallel scanning hatches, respectively. And all hatches constitute a path of triangular mesh shape, and the path is ultimately saved in a CLI format file executable in a 3D printer;The thesis was concluded with a summary and prospect in the fifth chapter.更多还原